In an optical network, such as a Synchronous Digital Hierarchy (SDH) and a Synchronous Optical Network (SONET), constituted by different manufacturers, each device provider would provide its own network element management system or sub-network management system for device maintenance and service allocation. At present, network element management systems or sub-network management systems of a manufacturer can not manage the devices of other manufacturers due to the differences among the devices of different manufacturers and the un-unified software interface standards adopted by different manufacturers. When devices of different manufacturers connect with each other, Multiplex Section Shared Protection Ring (MS SPRING), Linear Multiplex Section Protection (Linear MSP), Dual Node Interconnection (DNI), and etc are adopted to protect services. These protecting methods relate to devices of many different manufacturers in different management domains. Therefore, the problem that faces the network element management system and the sub-network management system is how the network element management systems and the sub-network management systems of different manufacturers effectively manage the above-mentioned services on the borders of sub-networks as well as the protection features in their own management domains.
To solve the problem, the method of configuring a virtual NE in the network element management system or the sub-network management system is usually adopted. The virtual NE is a kind of logic “NE” which is configured in the network element management system or in the sub-network management system, (both are referred to as network management system hereinafter), and is used to facilitate the management of services or protections in the network or in the sub-network by the network management system. The “NE” is usually used to simulate all or some of the management functions, such as services and protection functions of devices of one or more other manufacturers. It does not always correspond to a certain actual physical device in an actual network. The device maintenance and service allocation on the border of the network and the sub-network are made more convenient through the virtual NE, thereby enhancing the efficiency of device maintenance in the network and the sub-network.
In the prior art, the adopted simulation methods of virtual NE mainly are Black-box and Gray-box simulation methods.
The Black-box simulation method is shown in FIG. 1. One or more Black-box virtual NEs can be used to simulate one or more physical devices which are in sub-network 2 consisting of devices of manufacturer B and are outside the management domain of the network management system of sub-network 1, which consists of devices of manufacturer A.
In the Black-box simulation method, the Black-box virtual NE is only a constituent element of network topology. It is used to constitute the network topology with other topology elements, such as NEs and links. However, the Black-box virtual NE is not provided with internal service features, so it can not provide device management functions, such as device configuration, service, and protection, for the maintenance personnel of the network.
The Gray-box simulation method is shown in FIG. 2, which can also be used to illustrate the networking of White-box virtual NEs. As shown in FIG. 2, one or more Gray-box virtual NEs can be used to simulate one or more physical devices which are in sub-network 2 consisting of devices of manufacture B and are outside the management domain of the network management system of sub-network 1, which consists of devices of manufacturer A.
The Gray-box virtual NE is a constituent element of network topology while supporting some NE management functions, such as services. Compared with the Black-box virtual NE, the device simulation function provided by the Gray-box virtual NE is much stronger. For instance, the Gray-box virtual NE supports virtual NE service configuration, simple end-to-end circuit allocation, and etc. However, a Gray-box virtual NE can not simulate some complicated management functions, such as MS SPRING, Linear MSP and DNI protection, due to less information contained in the Gray-box virtual NE.